The present invention relates to a drive device.
In recent years, so-called hybrid vehicles having an engine and rotating electrical machines such as a generator and a motor as a driving force source of a vehicle have attracted attention in terms of fuel economy and environmental protection. A drive device for such hybrid vehicles requires a control device for controlling the rotating electrical machines. The rotating electrical machines and the control device are operated in combination and are connected through connection members such as power cables. For convenience of mounting on a vehicle, it is desirable to integrate the rotating electrical machines and the control device in one case. For example, Japanese Patent Application Publication No. JP-A-2004-343845 (Paragraph 0022, FIG. 1) discloses a drive device in which an inverter case accommodating a control device is integrally provided on top of a drive device case accommodating two rotating electrical machines, a differential gear unit, and the like.
Japanese Patent Application Publication No. JP-A-2007-124764 (Paragraphs 0072-0077, FIG. 5) discloses a drive device as described below. This drive device includes: an input shaft connected to an engine; two rotating electrical machines; a differential gear unit having three rotating elements respectively connected to one of the two rotating electrical machines, the input shaft, and an output rotating element; and a control device for controlling the rotating electrical machines. Regarding an arrangement of components of the drive device, Japanese Patent Application Publication No. JP-A-2007-124764 (Paragraphs 0072-0077, FIG. 5) discloses that the two rotating electrical machines, the differential gear unit, and the input shaft are arranged coaxially, and components of the control device such as an inverter unit, a reactor, and a capacitor are arranged above the drive device. The control device is positioned so as to axially overlap one of the rotating electrical machines. The capacitor and the reactor, which are relatively large components among the components of the control device, are positioned on the opposite sides to each other with respect to a vertical plane extending through a rotation axis of the rotating electrical machine, whereby these relatively large components can be efficiently accommodated in a drive device case.